Helicopters & RNAV approaches

[Phoinix]

I'm in the fog with RNAV field of knowledge and I'd like to get a bit more understanding about it. I'm struggling to find any relevant information from the flight/training manuals so here it goes...

Looking at some web published documents, including Eurocontrols, we have PBN which sets the new standards for RNAV specifications. Specifically for approach proposes, they defined four:
- RNP APCH LNAV (Lateral Navigation only and relies on GPS).
- RNP APCH LNAV/VNAV (with Vertical Navigation added and relies on GPS and Barometric VNAV). This is also referred to as an APV Baro.
- RNP APCH LP (Localizer Performance only and relies on GPS and EGNOS, the European satellite-based augmentation system (SBAS)).
- RNP APCH LPV (with Vertical Navigation added and relies on GPS and EGNOS).
This is also referred to as an APV SBAS.

This is the Euro version of the system, the US has WAAS.

Looking at the todays helicopters, which levels of RNP APCH do the popular types fulfil? If the above Eurocontrol definitions are not in use on the airframes itself, which are?
- 412EPI uses the US version, so called WAAS. Which is the Euro equivalent of...?
- AW139 acc. to the training manual has RNP APCH capability, but to what extent?
- EC145, AW169: any RNP APCH capability?

What is the requirement for the RNP APCH equipment? Single/dual GPS units + Inertial system + ? Certification of course, but what are the basic components required for the popular RNAV approach?

Any help appreciated!

Cheers,
Jure

[casper64]

H135, H145, H160 and H175 with helionix have all of the above as far as I know... for SBAS based approaches dual SBAS capable NMS required....

[n5296s]

fwiw in the US you don't need anything special. As long as you have the correct certified equipment (e.g. Garmin GNS530W) you're good to go for LNAV and LPV. (VNAV requires special equipment but is never better than LPV anyway).

RNP approaches are a different story and generally require specific approval both for the aircraft and the pilot.

I have no idea how this is creatively reinterpreted in Europe.

[mnttech]

fwiw in the US you don't need anything special. As long as you have the correct certified equipment (e.g. Garmin GNS530W) you're good to go for LNAV and LPV.
That is not completely true. An indicator able to display the information, verification that the system is good enough in all bank and pitch angles, along with a RFMS is probably all required too, at least in the US.

For those having trouble sleeping, refer to the Major Repair and Alternation Job aid on https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afx/afs/afs300/

[n5296s]

I guess I kind of took that for granted as part of a certified installation. It also needs to be approved for IFR approaches, which any reasonable 530 installation will be, but it's technically possible to install one without getting the certification. (Actually that was the situation with my plane's 430 installation when I bought it - just some paperwork and $1000 or so to straighten it out).

Same applies to the RFMS (or AFMS) - when you do the installation they give you a manual, which you are required to keep in the aircraft, thereby ensuring that you are never tempted to spend time reading it.

[Phoinix]

Thank you guys. With your help I came to this document: https://egnos-user-support.essp-sas.eu/new_egnos_ops/sites/default/files/workshop2016/12.%20AIRBUS%20HELICOPTERS%20-%20Helicopters%20status%20on%20LPV%20capability.pdf

So it’s not only the gnss unit + certification, it’s also AFCS. Surprisingly, no word on Inertial system. Any clues as to where to get the single/dual unit some clarity?

Is WAAS and SBAS compatible? WAAS capable airframe in Europe?